/*
 * Copyright 2020-2030 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.wwl.stack.usecase;

import com.wwl.stack.ArrayStack;
import com.wwl.stack.Stack;

public class Solution {

    public boolean isValid(String s) {
        Stack<Character> stack = new ArrayStack<>();
        int length = s.length();
        for (int i = 0; i < length; i++) {
            char c = s.charAt(i);
            if (c == '{' || c == '(' || c == '[') {
                stack.push(c);
                continue;
            }
            if (stack.isEmpty()) {
                return false;
            }
            char top = stack.pop();
            if (top == '(' && c != ')') {
                return false;
            }
            if (top == '[' && c != ']') {
                return false;
            }
            if (top == '{' && c != '}') {
                return false;
            }
        }
        return stack.isEmpty();
    }

}
